[swift-dev] determine if decl comes from ObjC header

[Joe Groff]

> On Feb 19, 2016, at 2:25 PM, Rafkind, Jon via swift-dev <swift-dev at swift.org> wrote:
> 
> How can I determine if a swift declaration comes from a header file, such as UITextInputTraits from iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/System/Library/Frameworks/UIKit.framework/Headers/UITextInputTraits.h?
> 
> I tried this
> 
> swift::ProtocolDecl * protocol;
> if (protocol->getModuleContext() == context->getClangModuleLoader()->getImportedHeaderModule()){
> ...
> }
> 
> but the two modules are not equal. protocol->getModuleContext()->isSystemLibrary() is true, but I'm not sure thats enough information to distinguish protocols defined in header files versus ones that come from core swift libraries.
> 
> The reason I am asking about this is that properties are treated differently in swift code versus objective-c code.
> 
> protocol Test{
>  var number:Int { get }
> }
> 
> This protocol will have 3 members, a PatternBindingDecl, a VarDecl, and a FuncDecl that is a getter. The pattern binding and getter seem to be autogenerated by the parser/typechecker.
> 
> For a protocol defined in a header file such as
> 
> @protocol  UITextInputTraits <NSObject>
> @property(nonatomic) UITextAutocorrectionType autocorrectionType;
> @end
> 
> will only have one member, the VarDecl for autocorrectionType.
> 
> I would like to deal with the VarDecl only in the case that it is declared inside a header file.

That seems like an inconsistency we should fix, instead of trying to work around.

-Joe